Measles vaccine increases child survival beyond protecting against measles
Everybody always assumes that measles vaccine only affects the target infection, but in this report by Sade Oguntola, experts say that measles vaccine also lowers a child’s risk of dying from other infections, such as respiratory infections particularly for females.
A measles vaccine protects against measles infection. By introducing a bit of weakened virus, the immune system learns how to deal with it, so when a real measles virus comes along, it can eliminate it. Beyond this, however, researchers say that measles vaccine also increases child’s survival beyond protecting against measles.
Experts in the largest study to date on children in Ghana suggests that measles vaccination in the recommended sequence may have made an important contribution towards achieving the Millennium Development Goal 4 of reducing child mortality.
The researchers evaluated deaths in children vaccinated against measles after the third diphtheria, tetanus and pertussis (DTP3) vaccination and those who were not vaccinated against measles using routine vaccination and survival data for more than 38,000 children over a 17-year period in northern Ghana.
The researchers found that compared to measles-unvaccinated children, survival rates for measles-vaccinated children increased by 28 per cent in the first 12 months of follow-up and 18 per cent by five years of age.
Their findings, published in open access journal Frontiers in Public Health indicated that this effect was still present when children who had died from measles were excluded from the analysis, indicating that the measles vaccine has beneficial effects beyond direct prevention of measles.
Dr Ogunbosin, a consultant paediatrician at the University College Hospital (UCH), Ibadan, Oyo State stated that the lower child survival in children with measles is understandable given that the disease tends to lower their body immunity.
According to the paediatrician, such children were also more predisposed to vitamin A deficiency and infections like tuberculosis, pneumonia and diarrheal diseases as well as their complications, so reducing their chances of survival.
During that period, children who got measles were more likely to die from other infections due to the long-lasting depletion of immune memory cells caused by the virus.
The study had found a considerably stronger beneficial effect of measles vaccination for boys in comparison to girls. Measles unvaccinated boys had a 69 per cent higher risk of dying during one year of follow-up and a 43 per cent higher risk of dying when followed until five years of age. For girls, there was little difference.
The study’s authors say the reasons for this are unclear and recommend future studies to examine the sex-differential effect of measles vaccination on all-cause mortality.
In 2015, a paper published in Science offered a new explanation. The researchers found that measles predisposes children to all other infectious diseases for up to a few years. After fighting off measles, the immune system makes a comeback but has ‘forgotten’ what it once learnt. The child’s immune system has to start afresh to rebuild the immune protection against viruses and bacteria it had previously fought off.
Measles, along with tuberculosis, diphtheria, tetanus, pertussis and poliomyelitis, is one of the six childhood killer diseases targeted by the World Health Organisation (WHO) mass immunisation programmes. This highly contagious respiratory disease that attacks the lungs and breathing tubes infects nine in 10 people who are not vaccinated.
In most cases, children suffer through the contingencies of measles and survive. However, in rare cases, the disease can be deadly. In extreme situations, measles can cause pneumonia, lifelong brain damage, deafness, diarrhoea and related dehydration, and death.
Measles is spread through coughing and sneezing, contact with respiratory secretions or aerosols or close personal contact. It remains contagious in air or on surfaces for up to two hours. The period of greatest infectiousness occurs four days before the onset of rash and four days after the rash has appeared.
Initial symptoms include high-grade fever, cough, runny nose, red eyes and tiny white spots in the mouth. These usually appear between 10 and 12 days after infection. A rash later develops, spreading from the face downwards.
Katsina, Borno and Yobe states have taken the lead in Nigeria as cases of measles surge by 700 per cent in Africa for the first three months of 2019 compared to 2018.
Every state in Nigeria has recorded a case of measles in 2019, with a total of 2,113 suspected cases reported from 34 states in a single week — the last week of March.
The trend of measles cases has followed the same pattern throughout many years, with cases peaking in March, then gradually reducing to the lowest level in June, which was maintained throughout the rest of the year.
According to WHO, countries in Africa have experienced a resurgence of measles, including outbreaks reported in at least nine countries (Chad, Cameroon, DR Congo, Liberia, Guinea, Madagascar, Mali, Nigeria and Uganda) in the last 12 months.
As of 2017, WHO UNICEF coverage estimates that only 16 countries in the African Region had achieved 90 per cent or more immunisation coverage of the first dose of measles vaccine (MCV1). Across the region, MCV1 coverage has stagnated, at 70 to 73 per cent since 2009.
The outcome of several studies has shown that measles outbreaks are associated with factors that include weak measles case-based surveillance in some areas, lack of awareness about the disease among parents, vaccine stock-out, and lack of adequate cold chain equipment to preserve the vaccine in remote hard-to-reach areas.
But a child needs two doses of measles-containing vaccine for full coverage. “With the first dose of measles vaccine, about 15 per cent of children will not have sero-converted. So, they will need to take a second dose,” said Dr Ogunbosin.
But he condemned local remedies and interventions like rubbing pepper into the eyes of a convulsing child or putting the child’s leg into the fire because they tend to increase ill-health and deaths in children who had measles.
To increase Nigeria’s low measles coverage, he stressed the need for increased public awareness of the disease and its prevention. According to him, “our vaccination coverage are not very encouraging, there is the problem from the caregiver, likewise the programme side.”
Mr Olarinde Olaoye, Oyo state health educator, declared that although measles remains a serious disease, many mothers still do not know that vaccination is the only effective way to protect against it. They do not know that vaccination is the best way to get immunity against measles.
“The government has designed a lot of ways to ensure the measles vaccine is received free of charge. All that is left is for mothers or caregivers to go to the health centre that is closest to them and take the vaccine for their children.
“Even if the child has measles, the vaccine reduces its severity. The child will only get the sign; it will not knock him down. All centres offering routine immunisation have scheduled days they immunise against measles,” he said.
Mrs Eunice Niyilola, Oyo state’s immunisation officer said having received the first dose of measles-containing vaccine at nine months, the second dose will further help to boost the body’s immunity against the disease.
She declared that the last mass immunisation of children against measles in Oyo State was in January 2018, but had left some children in some hard-to-reach areas like Ori ire Local government area.